16:18 (watch on YouTube, opens in a new tab)Flexible Variables: Bend Them to Your Will! | TMUA (watch on YouTube, opens in a new tab)
Sometimes the quickest way through a question is to give the letters convenient values. Five increasingly challenging TMUA past-paper questions — triangle areas, cubic roots, graph intersections, the distance between roots and quadratic inequalities — showing how well-chosen values can dramatically simplify the work. It is a legitimate method rooted in logic: the correct general answer must work for every permitted choice of values, so an option that fails for your chosen values can be eliminated. When it works, and how to choose useful values.
- Substitution
- Elimination
- Exam strategy
- Past papers
Watch on YouTube →: Flexible Variables: Bend Them to Your Will! | TMUA (opens in a new tab)